The present invention relates to the field of firearms and, more particularly, to an improved device for the loading and firing of a pistol and having means providing double locking of the bolt with respect to the barrel.
The locking mechanism for the breech of a firearm using a cartridge powerful enough to require a locked breech is generally actuated by one of three methods:
(1) Short recoil: The barrel and breech bolt recoil together for a short distance, typically about three millimeters, by which time the bullet has left the barrel and the gas pressure has subsided, and at which time the two components are separated from each other by a cam, and the slide/bolt, typically one piece, is free to recoil independently, cock the firing mechanism, eject the spent cartridge case and chamber a new one in readiness for another shot. Most pistols firing cartridges more powerful than those falling in the "pocket pistol" category fall into this classification, and many are variants of the designs of John M. Browning. Many of these designs are functional and reliable, but have the drawback of being excessively bulky and heavy. When a manufacturer wants to make a lighter version of a pistol of this type, he is forced to make the frame of light alloy, which is neither as durable nor as easy to machine as steel.
(2) Long recoil: The barrel recoils with the bolt for the extent of its travel, thereby cocking the firing mechanism; then, the barrel is released and goes forward independently, ejecting the spent cartridge case; and, then, the bolt goes forward, chambering a fresh cartridge in readiness for another shot. Though this mechanism is common in shotguns, it has no advantages in pistol design, and no successful examples.
(3) Gas operation: The barrel, which is rigidly fixed to the frame, typically contains a small hole leading to a cylinder. On firing a shot, a part of the gas under pressure is bled into the cylinder and expands against a piston that operates the bolt. There are many examples of gas-operated rifles and shotguns, but no current production pistols, the principal reason being that previous designs depended on a rotating bolt with lugs to lock the breech. A rotating bolt with protruding lugs is not a drawback when used on a rifle or shotgun, where there is room for a certain amount of thickness at the breech, but, if bulk is an important consideration when laying down the parameters of a design, it is a serious drawback, and previous designs have not proved to be an improvement on more conventional short-recoil designs. It will be noted that all previous gas-operated pistol designs have had very short production lives, having been unsuccessful both commercially and mechanically.